How does an APC-7 connector work? Anyone got a formal specification?

I've been trying for some time to find a formal definition of the APC-7 connector, so that I can model an open-circuit APC-7 using a 3D EM simulator. I believe this was jointly designed by HP and Amphenol, but whilst I found an engineering drawing on the Amphenol wen site, I did not find it sufficient for my needs. But today something kit me. Is there some spring arrangement that allows the inner conductor to move a little? Unless there is, I can't see how it is practical to mate them together properly. * If they both protrude, then they will damage each other. * If one or more are recessed, by more than the protrusion of the other, they will never make a connection. * It will be impossible to mechanically machine them so that they are just close enough to make electrical contact, without damaging each other. Does the inner of an unterminated APC-7 stick out beyond the reference plane? If so, by how much - what are the limits on it? If I know this, I can model the APC-7 in an EM simulator, so derive the properties of an open from DC to many GHz. Dave

The APC-7 connector is a genderless connector. It has a shuttlecock type collet that floats in the center conductor on both connectors. There were two types. A four flute collet which was good to 12.4 GHz and a 6 flute collet good to 18 GHz. The basic specification of the center conductor is +.0000/ -.0005 inch with the collet removed. There should be absolutely no protrusion on any precision RF connector. The collet should collapse flush when compressed and rebound about .010 inch. When you install an open standard it will compress the collet to .0000/-.0001 inch. There is a pin in the open standard that performs this task. You should gauge your connetors to know exactly where they are at. Your calibration kit should have the proper tools to remove the collet and measure the connector. When done inspect the collet under a microscope to check for damage to the flute surfaces. You should also inspect the center conductor and ground plane for damage especially positive protrusions as they will damage anything mated to it.